Add metrics to keep track of the tab activate/deactivate cycle

chrome/browser/ui/tabs/tab_strip_model.cc

Index: chrome/browser/ui/tabs/tab_strip_model.cc
diff --git a/chrome/browser/ui/tabs/tab_strip_model.cc b/chrome/browser/ui/tabs/tab_strip_model.cc
index 7cf6ebd4b2e510b35b7210afb53f3871631b7ac3..6d6262c1e9bd7407278682f4276a593730ebd244 100644
--- a/chrome/browser/ui/tabs/tab_strip_model.cc
+++ b/chrome/browser/ui/tabs/tab_strip_model.cc
@@ -320,7 +320,7 @@ void TabStripModel::InsertWebContentsAt(int index,
   selection_model_.IncrementFrom(index);
 
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                    TabInsertedAt(contents, index, active));
+                    TabInsertedAt(this, contents, index, active));
   if (active) {
     ui::ListSelectionModel new_model;
     new_model.Copy(selection_model_);
@@ -658,8 +658,8 @@ void TabStripModel::SetTabPinned(int index, bool pinned) {
   }
 
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                    TabPinnedStateChanged(contents_data_[index]->web_contents(),
-                                          index));
+                    TabPinnedStateChanged(
+                        this, contents_data_[index]->web_contents(), index));
 }
 
 bool TabStripModel::IsTabPinned(int index) const {